Fan attachment apparatus for fan component assemblies

ABSTRACT

A fan attachment is provided to attach a fan assembly to a cap of a heat exchanger. The fan attachment includes a feature to manage wires going to the fan motor, a notch for a thermister to sense temperature, snap hooks to be engaged by receiving tabs of the cap, a keying shear load feature to radially align the fan attachment and cap, and Z-height tolerance springs to bias the fan attachment away from the cap. The cap has features to interact with those of the fan attachment, including receiving tabs. The fan attachment may be manually aligned and forced so that the snap hooks are received and engaged by the receiving tabs. Additionally, the snap hooks and keying feature are, in combination, capable of supporting fan and attach mechanism in an undamaged condition during 25 g-force shock to the heat exchanger.

BACKGROUND

1. Field

One or more embodiments related generally to components and componentassemblies for cooling electronic devices. More particularly, one ormore embodiments relate to fan component assemblies, such as forattaching a fan assembly to a heat exchanger assembly of a computer.

2. Background

Electronic devices, such as computing devices, often require cooling ofelectronic circuitry, components, chips, disc drives, powertransformers, and the like. Computing devices contemplated includepersonal computers (PC), desktop computers, computing systems, portablecomputing devices, handheld computing devices, telephones, cellularphones, game devices, Internet related computing devices, servers,televisions, video monitors or displays, digital video disk (DVD)players, set top boxes, as well as video storage and editing devices. Insome cases, the computing device will have a main memory coupled to aprocessor, an operating system and other application programs to beexecuted by the processor.

For example, a printed circuit board (PCB), semiconductor chip package,semiconductor chip, power transformer, processor, central processingunit (CPU), memory chip, or other electronic device of a computer may bethermally coupled or attached to a heat exchanger that is cooled by afan, such as by the fan blowing air onto the heat exchanger.

Typically, such fans are mounted independently of the heat exchanger orelectronic device or devices they are to cool. For instance, a fan mayhave a cowling or external frame with holes running through the cornersof the frame to allow the fan and frame to be attached to internalstructure or the case of a computer. Specifically, current fanstypically include a frame around the blade component, and a pattern ofholes in the corners of the frame component to allow the fan to befastened to the computer by putting mounting hardware, such as screws orother similar hardware through the holes and into the frame or internalstructure of the computer.

However, such fan and frame assemblies require a frame for attachment tothe computer; are not attached and/or proximate to a heat sink; and maynot provide adequate cooling capacity or power, and thus may be unableto provide more than 100 watts of cooling.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features, aspects and advantages will become more thoroughlyapparent from the following detailed description, the set of claims, andaccompanying drawings in which:

FIG. 1 is a side perspective view of a fan assembly attached to a cap ofa heat exchanger by a fan attachment component.

FIG. 2 shows the fan assembly, cap, fan attachment, and heat exchangerof FIG. 1 prior to attachment of the fan attachment to the cap.

FIG. 3 a is a top perspective view of a fan attachment.

FIG. 3 b is a bottom perspective view of a fan attachment.

FIG. 4 is a side perspective view of fan assembly components, a fanattachment, a cap, and a heat exchanger prior to attachment of the fanattachment to the cap, showing snap hooks of the fan attachment andreceiving tabs of the cap to receive and engage the snap hooks.

FIG. 5 a is side perspective view of snap hooks of a fan attachment andreceiving tabs of a cap.

FIG. 5 b is another side perspective view of snap hooks of a fanattachment and receiving tabs of a cap.

FIG. 6 a is a cross-sectional schematic view of a snap hook of a fanattachment and the receiving tab of a cap prior to the receiving tabreceiving the snap hook.

FIG. 6 b is a cross-sectional schematic view of a snap hook of a fanattachment and a receiving tab of a cap during the receiving tabreceiving of the snap hook and prior to the receiving tab engaging thesnap hook.

FIG. 6 c is a cross-sectional schematic view of a snap hook of a fanattachment and a receiving tab of a cap after receiving tab receiving ofthe snap hook and during receiving tab engaging of the snap hook.

DETAILED DESCRIPTION

According to embodiments, a fan or a fan assembly may be attached to aheat sink or heat exchanger using a “fan attachment”. The fan attachmentmay be described as an apparatus or component of a system including acap and/or heat exchanger apparatus or component. Specifically, the heatexchanger may be part of a heat exchanger assembly having a cap and thefan may be part of a fan assembly having a fan, where each assembly hasvarious features, including features for alignment, receipt andengagement to couple or attach one assembly to the other assembly. Forexample, the fan attachment may include various features such as a wiremanagement feature, a thermister notch, snap hooks, a keying shear loadfeature, Z-height tolerance springs, a receiving tab feature, and/or akeying feature. Also, the fan assembly (which may include the fanattachment) may exclude or not require a cowling or frame, such as formounting the fan to internal structure or a frame of a computer, becausethe fan attachment provides sufficient mounting of the fan assembly tothe heat exchanger. Moreover, the proximity and direct attachment ormounting of the fan assembly to the heat exchanger (e.g., such as by thefan attachment touching, engaging, or being directly attached orconnected to a cap of the heat exchanger) allows for increased cooling.Specifically, using such an arrangement, the proximity of the locationof the fan to the heat exchanger causes more of the air blown by the fanto go into the heat exchanger, than locating the fan farther from theheat exchanger. For instance, the proximity of the fan to the heatexchanger may be a factor contributing to the system of the exchangerand fan producing a higher performing heat exchange, such as producingcooling of equal to or greater than 100 watts of power. Also, theproximity of the fan to the heat exchanger may cause most (e.g., morethan 50, 60, 70, 80, or 90 percent) of the air blown by the fan to gointo the heat exchanger.

Reference in the specification to “embodiment”, “embodiments”, “oneembodiment”, and “an embodiment” of the present invention means that aparticular feature, component, structure, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe present invention. Thus, the appearance of those phrases in variousplaces throughout the specification are not necessarily all referring tothe same embodiment. Moreover, in some cases, the fan attachment may beconsidered a component, a fan component, a part of a fan componentassembly or fan assembly of an electronic device or computer to beattached to a heat exchanger, a component of a heat exchanger, or a capof a heat exchanger of an electronic device or computer.

Also, directional references such as top, side, bottom, upper, lower,vertical, horizontal, outer, inner, above, below, beside, within, andthe like may be relative terms, such as with regard to the dispositionor orientation of various features or component. Thus, such terms arenot to be limiting, but are to provide an example of such orientations,positions, locations, and descriptions. For instance, although certaindescriptions and drawing show the heat exchanger, cap, fan attach andfan (e.g., components of the system) in vertical alignment, such asdisposed or mounted on a horizontal surface with respect to the surfaceof the Earth, it is also considered that the may be disposed or mountedon a surface other than horizontal, such as a vertical or angledsurface. Thus, descriptions of up, down, top, bottom, vertical,horizontal and the like are relative terms and may have other meaningswhen the components of the system are mounted other than in verticalalignment.

FIG. 1 is a side perspective view of a fan assembly attached to a cap ofa heat exchanger by a fan attachment component. FIG. 1 shows system 100including fan assembly 110 attached to heat exchanger 160. Fan assembly110 includes fan 120 and fan attachment 130. Heat exchanger 160 includescap 170, such as to index with, attach to, and allow features to worktogether with a fan attachment or a fan assembly. Heat exchanger 160 mayalso include vanes 162 such as to provide increased cooling surface areafor the fan to blow air upon to increase cooling capability of the heatexchanger 160 and fan assembly.

Fan attachment 130 is attached to cap 170, and vice versa, thusattaching fan assembly 110 to heat exchanger 160, and vice versa. Fanattachment 130 may also be described as attached to (and/or between) cap170 of the heat exchanger and fan 120. For example, a number of snaphooks of fan attachment 130 may be engaged by a number of receiving tabsof cap 170 to secure, engage, attach, hold, or mount fan assembly 110(e.g., fan attachment 130) to exchanger 160 (e.g., cap 170). Prior tosuch engaging, the snap hooks may be aligned with, mated with, orreceived by the receiving tabs. For instance, fan attachment 130 may beindexed, or aligned with cap 170 so that the snap hooks are aligned,mate with, or are received by receiving tabs of cap 170. Then, or duringreceiving of the snap hooks by the receiving tabs, upper portion UP offan 120 may be pushed downwards towards exchanger 160 until the snaphooks are engaged, held, secured, attached, or mounted to the receivingtabs. Also, cap 170 may define a cylinder or cylindrical perimeter (oranother perimeter matching the shape of perimeter 132) under the fanattachment.

Fan attachment 130 may be considered a component of fan assembly 110 andcap 170 may be considered a component of heat exchanger 160. Fanassembly 110 may include various other components, and components of fanassembly 110 may include various features. For example, fan assembly 110may include a motor, a fan control (such as circuitry on a printedcircuit board (PCB)) for controlling the speed of fan 120, a bearing toallow fan 120 to spin with respect to fan attachment 130, the motor, cap170, and/or heat exchanger 160.

Similarly, heat exchanger 160 may include components other than cap 170having various features. For example, heat exchanger 160 may be attachedto, coupled to, thermally coupled to, or otherwise provide cooling foran electronic device, such as a chip package, semiconductor chip, and/ora processor. Specifically, a chip package may be mounted below heatexchanger 160 and thermally connected to heat exchanger 160 such as bythermally conductive epoxy, attachment, or contact between the heatexchanger and the package.

Heat exchanger 160 may be, or may be part of a heat exchanger assembly(e.g., an assembly having more components than shown or describedherein). In some cases, heat exchanger 160 may provide liquid cooling,and/or be a liquid cooling heat exchanger. Thus, it can be appreciatedthat coolant lines may extend from heat exchanger 160 to be thermallycoupled to an electronic device, thus providing for cooling of thedevice. For instance, vanes 162 may be thermally coupled to a processorusing a liquid coolant and/or a solid heat exchange material.

Fan 120 may be a cooling fan for moving or blowing air such as to spinin a counter-clockwise direction to blow air onto or into heat exchanger160. Fan 120 may have a mass of between 50 and 100 grams, such as a massof approximately 75, 80, 84, 86, 88, 90, 95 grams, or a mass in a rangebetween any of those numbers. Although fan 120 is shown having five fanblades, it can be appreciated that fan 120 may include more or less thanfive blades, such as by having two, three, four, six, eight, or tenblades. Similarly, heat exchanger 160 is shown having a number ofcooling vanes 162 extending radially away from cap 170 below fan 120,and for an axis running upwards through the center of heat exchanger160. For instance, cap 170 may define or form a cylinder within heatexchanger 160, below fan attachment 130.

FIG. 1 shows fan assembly 110, fan 120, fan attachment 130, cap 170,and/or heat exchanger 160 in their expected use disposition ororientation. Specifically, fan attachment 130 is attaching assembly 110to exchanger 160 such that fan 120 may rotate at a sufficient speed(e.g., rotational speed in a counter-clockwise direction) to blow asufficient amount of air or move a sufficient amount of air onto, into,or through heat exchanger 160 to provide a desired amount of cooling.The desired amount of cooling may be providing cooling of 50, 60, 70,80, 90, 100, 110, 120, 130, watts or a range between any of thosenumbers of watts of cooling. For example, an actual cooling capacity forthe components of FIG. 1 may provide 130 watts of cooling, such coolingor cooling greater than that typically experienced by a fan arrangement,such as described in the background, may be increased since fan assembly110 is attached to, proximate to, or separated only by distance D fromthe top of heat exchanger 160 (see also discussion of distance D in FIG.4). Distance D may define a height or proximity between the bottom ofthe blades of fan 120 and the top of vanes 162 of exchanger 160.

FIG. 2 shows the fan assembly, cap, fan attachment, and heat exchangerof FIG. 1 prior to attachment of the fan attachment to the cap. FIG. 2shows system 200 including fan assembly 110 prior to attachment of thatassembly to heat exchanger 160. Thus, in FIG. 2, snap hooks of fanattachment 130 may not yet be received by or engaged by snap hooks ofcap 170. FIG. 2 shows fan attachment 130 including outer perimeter 132and snap hooks 140.

FIG. 2 also shows vanes 162 of exchanger 160. Heat exchanger 160 mayhave more or less vanes than that shown in FIG. 1 or 2. It is alsoconsidered that fan attachment 130 and/or cap 170 may be coupled tovarious other types of heat exchangers or electronic devices, such aswhere cap 170 is a component of, part of, or attached to a differenttype or shape of heat exchanger or electronic device.

Outer perimeter 132 may define or form an outermost perimeter surface,perimeter, or shape of fan attachment 130 (which may or may not excludecertain features of fan attachment 130, such as a wire managementfeature). Snap hooks 140 may represent a pair of snap hooks at two,three, four, five, six, or more locations around the perimeter of outerperimeter 132.

Cap 170 is shown having receiving tabs 180 formed on or in upper surface172 of cap 170. Surface 172 may be described as a disc shaped surface(e.g., of a cylindrically shaped cap portion) that the tabs extendperpendicularly away from (e.g., up and away from the disc shapedsurface). Although FIG. 2 shows four receiving tabs, it can beappreciated that more or less receiving tabs, such as two, three, four,five, six, or more receiving tabs may be used. Specifically, a receivingtab may exist at upper surface 172 for each pair of snap hooks 140. Forinstance, a receiving tab may be located on cap 170 at a location of (ora location “corresponding” to) a location of each pair of snap hooks,such as to receive and engage each pair of snap hooks once properlyindexed (e.g., by keying and shear load 370, keying feature 475, and orsurfaces of the snap hooks and tabs as described herein).

For instance, outer perimeter 132 may define a cylinder, oval, circular,square, polyhedron, or other perimeter surface or shape having armsending in snap hooks to be received and engaged by receiving tabs 180.The majority of the outer surface of perimeter 132 may be flat and/orhave texture. The majority of the outer surface of perimeter 132 mayhave a cross sectional shape that is or is not vertically planar. Insome cases, the outer surface of perimeter 132 may form the outside of acylindrical shape broken only by the snap hooks, slots and otherfeatures of fan attachment 132 described herein. Alternatively, theouter surface of perimeter 132 may also be broken by other features notmentioned herein.

FIG. 2 also shows arrows 210 that may represent the direction, force,and/or pressure for attaching fan attachment 130 to cap 170. Forexample, arrows 210 may represent manual force MF shown being applied toupper portion UP of fan 120 in order to have snap hooks 140 received byand engaged by receiving tabs 180. Manual force MF may be a force ofbetween 2 and 3.7 pounds of pressure on upper portion UP, such as bybeing 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.7, or a rangebetween any of those numbers of pounds of pressure applied to upperportion UP. For example, manual force, MF may be created by a person,machine, or robot pressing on upper portion UP. Similarly, arrows 210may represent a force as described above for manual force MF, such aswhere the force is generated other than at upper portion UP of fan 120.Thus, arrows 210 may represent a force capable of being generated by aperson, such as the force with which snap hooks 140 are pressed towardsreceiving tabs 180 such as to be received by and engaged by receivingtabs 180.

It is considered that attachment of assembly 110 or fan attachment 130to exchanger 160 or cap 170 may be described by receiving and/orengagement of snap hooks 140 by receiving tabs 180. In some cases, suchattachment may also include lifting or biasing of the fan attachmentaway from the cap by springs, such as will be described later.

FIG. 3 a is a top perspective view of a fan attachment. FIG. 3 b is abottom perspective view of a fan attachment. FIG. 3 a and 3 b show fanattachment 130 having generally disk shape 301 around center axis 302,top surface 303 and bottom surface 304. Radially distal from axis 302 isouter perimeter 132, such as a ring shaped outer perimeter, having anumber or arms, such as arm 135 of the outer perimeter surface. One ormore of arms 135 may define openings 134 in or through the disk shapebetween axis 302 and outer perimeter 132 (e.g., between axis 302 andarms 135). It may also be said that outer perimeter 132 or an inner ringsurface of arms 135 may define openings 134, where the openings exist.Arms 135, ends 335 of arm 135, and/or portions of outer perimeter 132may define or be separated by slot 342 through the outer perimetersurface and to an opening of openings 134. Specifically, adjacent ends335 of adjacent arms 135 may define a slots through outer perimetersurface 132 and to opening 134. Pairs of adjacent snap hooks 140 are onthe outer perimeter surface, where each snap hook has wedge shape 136pointing from top surface 303 towards bottom surface 302 and extendsradially outwards from outer perimeter surface 132 on either side of theslot. Fan attachment 130 also includes wire management feature 320,thermister keep out notch 310, pairs of snap hooks 140, keying and shearload 370, and Z-height tolerance springs 380.

FIGS. 3 a and 3 b also show thermister keep out notch 310 defined bysurfaces of fan attach 130 and having a geometry and/or surfaces toprovide an opening, location or clearance for locating or mounting athermister component for sensing the ambient air around the fan. Thethermister component can be electrically (e.g., using wires) attached tothe fan motor or fan motor control PCB to provide feedback ortemperature data sensed for the ambient air around the fan so that a fanspeed (e.g., revolutions per minute (RPM)) may be select or set toprovide sufficient cooling or a sufficient amount of air into exchanger160. It can be appreciated that although surfaces defining notch 310 areshown defining a rectangular notch, various other shapes and sizes maybe used, as long as the shape and size is sufficient for receiving andretaining a thermister (e.g., such as a shape equal to a x-section ofthe thermister).

Wire management feature 320 includes or defines openings 322 and 325such as to route power and control wires from a fan motor of a fancoupled to the fan attachment (or a fan motor PCB for controlling thefan) to a power header for plugging into a power source. Thus, feature320, surfaces defining opening 322 and/or opening 325 may prevent thewires from contacting blades of the fan as they rotate, such as byproviding or defining openings to route the wires out of the fanassembly, under the fan blades, and/or into the heat exchanger.

FIGS. 3 a and 3 b also show snap hooks 140 each having wedge shape 136,and opening 134 behind outer perimeter 132 where snap hooks 140 arelocated at or on perimeter 132. Snap hooks 140 may be described ashaving wedge shape 136 located on, pointing down along, and/or extendingoutwards from outer perimeter surface 132 (e.g., at locations at whichsnap hooks are located on perimeter 132). Each of the snap hooks of thepair may be described as pairs of adjacent snap hooks on either side ofa slot or opening through or dividing arms 135 along or of perimeter132. Thus, in addition to being defined by other structures such asarms, arm ends, and the out perimeter surface, a slot may also bedefined by adjacent snap hooks. FIGS. 3 a and 3 b show four pair for atotal of eight snap hooks, although other numbers of pairs greater orless than four pair are considered.

The snap hooks may be described as mounted or located on perimeter 132(e.g., as a wedge shape pointing down) at the end of arms 135. A snaphook may be described as a wedge shape pointing down along perimeter 132at the end of arm 135. Arm 135 may be an arm of fan attachment 130defined by or part of perimeter 132. Also, arm 135 may define perimeter132, opening 134 and the slot separating the snap hook from the adjacentsnap hook (and the end of the adjacent arm). Arm 135 may be sufficientlyflexible so a force or pressure on the snap hook (e.g., such as inwardstowards the axis or center of the fan attachment) causes the arm to flexor move back (e.g., at the end of the arm where the snap hook is) intoopening 134. The arm flexing or moving back may include or also bedescribed by saying that the snap hook flexes or moves back, and viceversa.

FIGS. 3 a and 3 b also show keying and shear load 370 defining gap 372to properly align fan attachment 130, with an index or a protrusion ofcap 170 having receiving tabs 180. For instance, surfaces defining gap372 may be used to index or properly align fan attachment 130, radially,with an index or a protrusion of cap 170 so that snap hooks of fanattachment 130 are properly align, radially, with receiving tabs of cap170.

FIGS. 3 a and 3 b also show Z-height tolerance springs 380, such assprings having a sufficient spring force “k” to keep fan attachment 130,fan assembly 110, and/or components thereof from rattling or reduce anamount of rattling caused by clearances between cap 170 and fanattachment 130. Keeping from ratting or reducing rattling can beaccomplished or caused by the springs, collectively, forcing, pressing,or lifting fan attachment 130 away, up, and/or vertically away fromreceiving tabs 180, to hold surfaces, such as top surfaces, of snaphooks 140 against a top inner surface of the receiving tabs. Thus, thecollective force may be sufficient to ensure that a fan coupled to fanattachment 130 is at a known position relative to the heat exchanger(e.g., in three dimensional location, with respect to the “yawl” axis orrotational axis of the fan), such as to have the bottom of blades of thefan at a known distance D (see FIG. 1) in height above the top surfacesof vanes of the heat exchanger. It can be appreciated that the springscan perform a similar function for keeping the blades above structures,electronic devices, or other cooling components in addition to a heatexchanger, such as when a heat exchanger is not used. It can beappreciated that although springs 380 are shown having four springs,various numbers of springs, such as two, three, five, six, eight, ormore springs may be used, as long as the springs provide a similar forcefor performing the functions described above.

FIG. 4 is a side perspective view of fan assembly components, a fanattachment, a cap, and a heat exchanger prior to attachment of the fanattachment to the cap, showing snap hooks of the fan attachment andreceiving tabs of the cap to receive and engage the snap hooks. FIG. 4shows system 400 including components of fan assembly 110 and heatexchanger 160. Specifically, motor 410, bearing 420, thermistercomponent 430, fan motor control PCB 440, and fan attachment 130 of fanassembly 110 are shown. Similarly, cap 170 of heat exchanger 160 isshown. FIG. 4 also shows features of fan attachment 130 including outerperimeter 132, opening 134, thermister notch 310, snap hooks 140, slot342, and wire management feature 320. Slot 342 may represent a slotbetween, separating, or dividing a pair of snap hooks, such that eachsnap hook or wedge shape of each snap hook may point down along andextend outwards from perimeter 132 on either side of slot 342.

Also, as shown in FIG. 4, surfaces defining thermister notch 310 mayhave a geometry, size and surfaces to provide clearances for thermistercomponent 430, which may be attached to or part of PCB 440 for sensingthe ambient air (e.g., a temperature of the air) around the fan so thatthe circuitry of PCB 440 can set or change the fan speed to providesufficient cooling to heat exchanger 160.

As shown in FIG. 4, management feature 320 may include or defineopenings to mount wires from motor 410 and/or PCB 440 to a power header(not shown). Although feature 320 is shown having a curved shape,surfaces defining two openings at openings 322, and surfaces definingone opening for opening 325, it can be appreciated that various othershapes, surfaces defining openings, and/or numbers of openings may beused for feature 320. Moreover, feature 320 may include structures tofix and/or restrain the wires, such as wherein the openings are smaller,include rubber, or other structure to hold or restrain a wire from beingpulled one direction or another through feature 320.

Motor 410 may be a motor that rotates with fan 120 or rotates a shaftattached to fan 120. Motor 410 may be a motor for spinning a fan withsufficient speed, or RPMs, to provide cooling as described herein.Bearing 420 may be a bearing for rotating fan 120. PCB 440 may be a PCBincluding circuitry, logic, and/or control circuitry to control thespeed of rotation of fan 120 as described herein. Also, thermistercomponent 430 may be a thermister to fit within surfaces definingthermister notch 310 and may provide sufficient feedback or signal ofthe ambient air around fan 120 to allow PCB 440 to adjust the speed ofthe fan to provide sufficient cooling. Specifically, the rotationalspeed of the fan may be increased to provide additional cooling (e.g.,increase a rate of cooling of exchanger 160) when the ambienttemperature around the fan exceeds a high temperature threshold; and/ordecreased to reduce cooling (e.g., decrease a rate of cooling ofexchanger 160) when the ambient temperature around the fan is below alow temperature threshold.

As shown in FIG. 4, gap 372 defined by surfaces of keying and shear loadfeature 370 may align fan attachment 130 with cap 170. The surfacesdefining gap 372 may align with or index protrusion 477 defined bysurfaces of keying feature index 475 of cap 170. It can be appreciatedthat although keying and shear load 370 is shown defining gap 372 with acertain size and shape, various sizes and shapes for gap 372 may be usedas long as they are sufficient for being indexed by an index orprotrusion. In some cases, although protrusion 477 is shown having acurved shape, it can be appreciated that protrusion 477 can have variousshapes and/or sizes as appropriate for indexing or being engaged bysurfaces of keying and shear load 370 that define gap 372. Specifically,feature 370, surfaces defining gap 372, index 475 and/or protrusion 477may have surfaces, shape, size, and/or material sufficient to index fanattachment 130 during receiving and engaging of snap hooks 140 byreceiving tabs 180 to resist rotation and/or provide shear resistancefor fan attachment 130 with respect to cap 170. For instance, engagementof protrusion 477 and surfaces defining gap 372 (e.g., during or whilesnap hooks engage index tabs) may prohibit rotation and/or provide shearresistance for fan attachment 130 with respect to cap 170 duringrotation of fan 120, such as during use of fan 120, during or as aresult of a 20 g-30 g shock (e.g., such an from an impact in anydirection, to a computer case or motherboard on which the heat exchangeris mounted), without damaging material and/or surfaces defining gap 372and/or protrusion 477.

Also, snap hooks 140 may have a wedge shape and/or surfaces to bereceived by and engaged by openings defined by receiving tabs 180 sothat the snap hooks snap-in or spring-snap into the receiving tabsand/or engaged by the receiving tabs to resist rotation and provideshear resistance for the fan attachment during rotation of the fan. Forinstance, the snap hooks may be snap-in type hooks or spring snap typehooks to snapped into opening of the receiving tabs (e.g., into surfacesdefining the openings) to maintain attachment of the fan to the heatsink.

Also, the indexing by feature 370 and index 475, and/or engagement ofsnap hooks 140 by receiving tabs 180 may provide sufficient resistanceof rotation, shear resistance, indexing, engagement of snap hooks byreceiving tabs, and/or attachment of fan attachment 130 by cap 170 toretain or maintain indexing, engagement and/or attachment during a shockto an electronic device, motherboard, system board, PCB, casing, outersurfaces, or inner structure of an electronic or computer device towhich heat exchanger 160 and/or cap 170 are coupled, attached, ormounted (e.g., such as being firmly and directly connected to transferthe shock). Specifically, the indexing, engagement, and/or attachmentmay be sufficient to be retained or maintained during a 20 g (e.g., a“G” force or force of the acceleration of the Earths gravity upon anobject near the surface of the Earth, which is considered one “g”), 25g, 30 g, 35 g, or a g-forces shock in a range between any of thosenumbers in any direction to the electronic device, system board, orcomputer to which cap 170 is coupled. This the indexing, engagement,and/or attachment of the snap hooks and keying feature, in combination,may be capable of supporting fan and attach mechanism in an undamagedcondition during 25 g-force shock to the heat exchanger. Similarly, theindexing, engagement, and/or attachment may be sufficient to be retainedor maintained while providing cooling as described herein. The receivingand engagement of snap hooks by receiving tabs is described furtherbelow.

FIG. 4 also shows Z-height tolerance springs 380 to keep from rattlingor reduce rattling of fan attachment 130, bearing 420, motor 410,thermister component 430, PCB 440, and/or feature 320 by lifting fanattachment 130 away from receiving tabs 180, surface 172, and/or cap 170(e.g., biasing the fan attachment away from the receiving tabs so thatsurfaces 546 engage surfaces 594 of FIG. 5). Specifically, FIG. 4 showsdistance D1 as the height of outer perimeter 132 of fan attachment 130.In some cases distance D may equal distance D1. It can be appreciatedthat distance D may be a higher less than or great than the height ofperimeter 132. For instance, distance D may be a height of 1, 2, 3, 8,10, 20, 40, 80 millimeters (mm), or any combination of thereof or rangebetween any combination of thereof above a top surface of exchanger 160and/or upper surface 172. Thus, distance D may correspond to thedistance between the bottom of the blades of the fan and the top of theheat exchanger 160 and/or vanes 162. As such, in embodiment, springs 380bias or force fan attachment 130 away from surface 172 such that anupper surface of snap hooks 140 is biased against and inner uppersurface of receiving tabs 180 to keep the bottom of the fan blades aheight equal to distance D above vanes of heat exchanger 160.

Z-height tolerance springs 380 may have a shape and size, and a materialsufficient to bias fan attachment 130 during receiving and engaging ofsnap hooks 140 by receiving tabs 180 to maintain distance D, such as byresisting reduction of distance D of fan attachment 130 with respect tocap 170. For instance, the force provided by Z-height tolerance springs380 (e.g., during or while snap hooks engage index tabs) may properlybias fan attachment 130 so that the blades maintain distance D above thetop of the exchanger (e.g., vanes) during rotation of fan 120, such asduring use of fan 120, during or as a result of a 20 g-30 g forcesshock, without damaging the material of Z-height tolerance springs 380.

FIG. 5 a is side perspective view of snap hooks of a fan attachment andreceiving tabs of a cap. FIG. 5 b is another side perspective view ofsnap hooks of a fan attachment and receiving tabs of a cap. FIGS. 5 aand 5 b show features, geometry, and surfaces of snap hooks 140 of fanattachment 130; and of receiving tabs 180 of cap 170. Specifically,FIGS. 5 a and 5 b show fan attachment 130 including outer perimetersurface 132 having vertical slot 342, and pairs of adjacent snap hooks140 each having wedge shape 136 pointing downwards along and extendingoutwards from outer perimeter surface 132 on either side of slot 342.Each wedge may be described as located on surface 132 adjacent to orbeside slot 342. Also, each pair of adjacent snap hooks may be receivedby opening 590 and engaged by the surfaces of receiving tab 180 thatdefine opening 590. For example, each pair of snap hooks may have anumber of surfaces to be received by and engaged by a number of innerperimeter surfaces that define opening 590. In some cases, the snaphooks or wedge shapes may be defined by the surfaces to be received andengaged. Similarly, openings 590 may be defined by tabs 180 and/orsurfaces of tabs 180 to receive and engage surfaces of hooks 140.

In more detail, FIGS. 5 a and 5 b show each snap hook 140 or wedge shape136 having top surface 546, outside side surface 548, inside sidesurface 550 and lower surface 544. Top surface 546 may be parallel (orapproximately parallel, such as within 5 degrees of parallel) to topsurface 303 of disc shape 301 of the fan attachment. Outside sidesurface 548 may be perpendicular (or approximately perpendicular, suchas within 5 degrees of perpendicular) to top surface 303 and/or to outerperimeter surface 132. Inside side surface 550 may also be perpendicular(or approximately perpendicular, such as within 5 degrees ofperpendicular) to top surface 303 and/or to outer perimeter surface 132.Additional descriptions for the surfaces include that lower surface 544may be described as angled away from outer perimeter surface 132 (e.g.away from the lower edge of surface 132), and may define a rectangular,square, and/or flat surface extending form the edge or surface ofsurface 132 along an outer edge of the outside side surface 548 andinside side surface 550 to an outer edge of top surface 546.Correspondingly, top surface 546 may be described as disposed away fromcap 170 or surface 172 and extending perpendicular to outer perimetersurface 132. Top surface 546 may define a rectangular, square, and/orflat top surface between the upper edges of the outside side surface548, the inside side surface 550 and the upper edge of the lower surface544. Outside side surface 548 and inside side surface 550 may bedisposed vertically and extend perpendicular to outer perimeter surface132. For instance, surface 548 and/or surface 550 may define atriangular and/or flat vertical surface between surface 132, an edge oftop surface 546, and an edge of lower surface 544. Inside side surfaces550 may be described as facing or dispose toward each other and/or slot342 and may form a planar surface extending into and including innersurface 444 of slot 342 (see FIG. 5 b).

Correspondingly, receiving tab 180 may include or define inner surfaces592, bottom inner surface 596, and top inner surface 594. Surfaces 592may be for receiving, engaging and/or restraining surfaces 548. Bottominner surface 596 may be for receiving, engaging and/or restrainingsurfaces 544. Also, top inner surface 594 may be for receiving, engagingand/or restraining surfaces 546. Inner surfaces 592, bottom innersurface 596, and top inner surface 594 may be said to define opening590.

Receiving tab 180 may also include or define front surface 582, outertop surface 587, outer side surfaces 586, upper surface 584, and backsurface 583. Inner surfaces 592 may define a rectangular, square, and/orflat top surface between surface 582 and 583 along an edge of surface594 and 596. Top inner surfaces 594 and/or bottom inner surface 596 maydefine a rectangular, square, and/or flat top surface between surface582 and 583 along an edge of surfaces 592. Surface 596 may be the samesurface 172. Front surface 582 and back surface 583 may also be said todefine opening 590.

Inner surfaces of or defining opening 590 may be described ascorresponding to or matched to surfaces of snap hooks 140. For instance,surface 548 may correspond to surface 544 during indexing and receivingof hooks 140 by tab 180. Also, surfaces 592 and/or surface 594 maycorrespond to surfaces 548 and/or surface 544, respectively, duringindexing, receiving, and engagement of hooks 140 by tab 180.

Upper surface 584 may be angled, cambered, and/or have a shapecorresponding to surface 544 to cause hook 140 to be indexed, received,and/or engaged by tab 180 as described herein (e.g., see FIG. 6 a-6C).Surface 587 may be optional, as upper surface 584 may extend from backsurface 583 to an edge of front surface 582. Alternatively, surface 587may exist, such as to define or select an angle, chamber or chamber ofsurface of 584 with respect to surface 544 of fan attachment 130.Specifically, lower surface 544 may be angled away from the surface ofperimeter 132 to cause the orientation, disposition or angle of surface544 and surface 584 (e.g. a plane defined by the surfaces) to match,correspond, be parallel, or be equal. Moreover, the angle may beselected or angled away such that the first contact between surface 544and surface 584, during proper receiving, indexing, or alignment createsa contact area of a plane, a line, or a point as designed or selected.

Thus, hook 140 (e.g., the end of arm 135 having the hook) and tab 180may flex away from each other during receiving and then upon dispositionof hook 140 within opening 590 may flex back towards each other so thatsurface 546 engages surface 594, thus defining engagement of hook 140 bytab 180. It can be appreciated that such engagement may include wheresurface 594 is matched to, corresponds to, is parallel to, or defines acontact shape of a plane or a line with surface 546.

Similarly, one or both surface(s) 548 may be indexed, oriented orrestrained by one or both surface(s) 592 during receiving and then upondisposition of hook 140 within opening 590 so that surface(s) 548 engagesurface(s) 592, thus also defining engagement of hook 140 by tab 180. Itcan be appreciated that such engagement may include where surface(s) 592are matched to, correspond to, are parallel to, or define a contactshape with surface(s) 548, such as a plane or a line of contact betweensurface 592 and 548.

FIG. 6 a is a cross-sectional schematic view of a snap hook of a fanattachment and the receiving tab of a cap prior to the receiving tabreceiving the snap hook. FIG. 6 a shows arm 135 of fan attachment 130having snap hook 140 at a location of outer perimeter 132. Snap hook 140is shown having top surface 546 and lower surface 544. FIG. 6 a alsoshows cap 170 having receiving tab 180 having upper surface 584, and topinner surface 594 of opening 590. It is considered that FIG. 6 a mayrepresent a pair of adjacent snap hooks (e.g., in profile so that onlyone is showing) of the receiving tab of a cap prior to the receiving tabreceiving the snap hook.

It can be appreciated that various surface shapes, textures and anglesfor upper surface 584 and/or surface 544 can be used or selected toprovide indexing, receiving, and/or engaging as described herein. Forexample, angle A1 of surface 544 from vertical surface of perimeter 132and angel A2 of surface 584 a horizontal plane can be selected to becomplimentary (e.g., to add up to 90 degrees). Alternatively, angle A1and A2 may in a range of between 5 to 10 degrees from complimentary.Also, angle A1 can be an angel between 30 degrees and 60 degrees. AngleA1 or A2 can be an angle of 35, 40, 45, 50, 55 degrees, or in a rangebetween any of those two numbers in degrees.

FIG. 6 b is a cross-sectional schematic view of a snap hook of a fanattachment and a receiving tab of a cap during the receiving tabreceiving of the snap hook and prior to the receiving tab engaging thesnap hook. FIG. 6 b shows receiving tab 180 receiving snap hook 140 suchas where contact between surface 544 and 584 defines a contact shape ofa plane, a line, or a point. For example, first contact between surfaces544 and 584 may define a contact shape of a plane or a line. It isconsidered that FIG. 6 b may represent a pair of adjacent snap hooks(e.g., in profile so that only one is showing) of the receiving tab of acap during the receiving tab receiving the snap hook and prior to thereceiving tab engaging the snap hook.

Then, as manual force MF (e.g., see description with respect to FIGS. 1and 2) forces surface 544 farther down with respect to surface 584, hook140 (e.g., the end of arm 135 having the hook) and tab 180 may flex awayfrom each other, such as to create a contact shape of a line or point.For example, arm force AF is shown representing the contact force orpressure of hook 140 (e.g., the end of arm 135 having the hook) and tab180 against each other in the radial direction (e.g., such as inwards,perpendicular to, towards the axis or center of the fan attachment bythe tab and away from that axis for the hook) that results from manualforce MF during receiving. Force AF may cause arm 135 to flex away ormove back (e.g., at the end of the arm where the snap hook is) intoopening 134. Force AF may be described as two equal force components, inopposite directions (e.g., at a point of contact between hook 140 andtab 180). Thus, in some cases, saying the snap hook flexes and the armflexes may be synonymous.

Specifically, FIG. 6 b shows flexing FR as a distance that back surface583 flexes outward from surface 132. Likewise, FIG. 6 b shows flexing FSas a total distance that surface 132 flexes away from surface 583. Inother words, flexing FR may describe a distance that tab 180 flexes awayfrom hook 140, and flexing FS may describe a distance that hook 140(e.g., the end of arm 135 having the hook) flexes away from tab 180 dueto a force between the hook and the tab at contact shape 610 (e.g., apoint or a line of contact). Flexing FR and FS may be described as twoequal flexing distances, in opposite directions (e.g., at a point ofcontact between hook 140 and tab 180). Force AF may be caused by the ashape, size, and/or material of arm 135 and/or tab 180 resisting flexingFR and FS, where flexing FR and FS is caused by manual force MF and/orthe shape, angle and/or size of hook 140, surface 544, surface 584,and/or tab 180. For a pair of snap hooks, FR and FS may be the same foreach snap hook, however AF required will be double for the pair of snaphooks.

According to embodiments, arm 135, hooks 140, and/or tab 180 may bedesigned (e.g., have a shape, size, and/or material sufficient) to flexduring alignment, receiving (e.g., caused by a manual force) andengaging so that after flexing during receiving, the arm 135, hooks 140,and/or tab 180 can “unflex” or return to its original shape withoutbecoming damaged or permanently deformed (e.g., be able to return towithin one to 10 percent of it's original profile, as shown in FIGS. 6a-6 c).

FIG. 6 c is a cross-sectional schematic view of a snap hook of a fanattachment and a receiving tab of a cap after receiving tab receiving ofthe snap hook and during receiving tab engaging of the snap hook. FIG. 6c shows hook 140 engaged by tab 180, surfaces of tab 180 and/or definingopening 590. It is considered that FIG. 6 c may represent a pair ofadjacent snap hooks (e.g., in profile so that only one is showing) of afan attachment and a receiving tab of a cap after receiving tabreceiving of the snap hook and during receiving tab engaging of the snaphook. Specifically, FIG. 6 c may represent locating a pair of snap hookswithin or between the plurality of corresponding surfaces definingopening 590 of the receiving tab.

As compared to FIG. 6 b, the hook and tab may have flexed back towardseach other (e.g., the components of force AF, flexing FR, and/or flexingFS are now zero or substantially zero). As compared to FIG. 6 a, thehook and tab in FIG. 6 c may not be flexed at all. For example, surface132 may be adjacent to, touching, abutted against, and/or parallel tosurface 583. Also, flex FR and/or flex FS (e.g., flexing of arm 135) maybe described as being zero in FIG. 6 c. Hook 140 being engaged by tab180 may also include one or both of surfaces 592 of opening 590 engagingcorresponding one or both of surfaces 548 of hook 140, such as to resistrotation and/or provide shear resistance of fan attachment 130 withrespect to cap 170.

Also, the engagement may include surface 594 engaging surface 546 and/orsurface 592 engaging surface 548, such as to prohibit disengagement ordetachment of hook 140 from tab 180 or opening 590. This engagement mayprohibit disengagement without components becoming damaged, during use(e.g., during rotation of the fan at a speed sufficient to providecooling), and/or as a result of a 20 g-30 g shock (e.g., a physicalshock having a force of between 20 and 30 g-forces to the heat sink).Also, one surface engaging another may be described by the surface beingadjacent to or touching, being restrained by, being maintained by, ornot moving beyond the other surface.

In other words, the engagement may describe a pair of hooks 140 beingsecured at a pair of outside side surfaces 548 by a pair of side innersurfaces 592, and/or top surface 546 secured by or engaged by top innersurface 594, such that a pair of snap hooks are restricted from, unableto, or otherwise prohibited from rotating, lifting off of, becomingdetached from, or leaving surfaces defining opening 590 without damage,breaking, or bending of snap hooks 140 and/or receiving tab 180. Thisrelationship may also be described as the hooks, a geometry of thehooks, and/or surfaces of the hooks being engaged by the tab, surfacesdefining the opening of the tab, and/or the geometry of those surfacesof the tab with sufficient resistance to prohibit disassembly,detachment or disengagement without damaging, breaking or bending thehooks or tab (e.g., at least one hook or tab must be damaged to detachthe fan assembly from the cap).

Similarly the engagement may include a pair of hooks 140 being securedat a pair of outside side surfaces 548 by a pair of side inner surfaces592, and/or top surface 546 secured by or engaged by top inner surface594, such that a pair of snap hooks are restricted from, unable to, orotherwise prohibited from rotating, lifting off of, becoming detachedfrom, or leaving tab 180, or surfaces defining opening 590 during use,such as during rotation of the fan for cooling. This relationship mayalso be described as the hooks, a geometry of the hooks, and/or surfacesof the hooks being engaged by the tab, surfaces defining the opening ofthe tab, and/or the geometry of those surfaces of the tab withsufficient resistance during use, such as during rotation of the fan forcooling, to prohibit disassembly, detachment or disengagement.

Likewise, the engagement may include a pair of hooks 140 being securedat a pair of outside side surfaces 548 by a pair of side inner surfaces592, and/or top surface 546 secured by or engaged by top inner surface594, such that a pair of snap hooks are restricted from, unable to, orotherwise prohibited from rotating, lifting off of, becoming detachedfrom, or leaving opening 590 during or as a result of a 20 g-30 g shock.This relationship may also be described as the hooks, a geometry of thehooks, and/or surfaces of the hooks being engaged by the tab, surfacesdefining the opening of the tab, and/or the geometry of those surfacesof the tab with sufficient resistance during or as a result of a 20 g-30g shock, to prohibit disassembly, detachment or disengagement.

The snap hooks, arms, and/or receiving tabs may have a shape, size,and/or material sufficient to provide the indexing, receiving (e.g.,flexing) and/or engagement described herein between the snap hooks andreceiving tabs (e.g., between the fan attachment and cap). In somecases, the engagement above includes a resistive force (e.g., similar toforce AF during receiving) caused by a shape, size, and/or material(e.g., without damaging the material) of arm 135 and/or tab 180resisting flexing (e.g., similar to resisting flexing FR and FS). Thisflexing resistance may be in response to or during a manual force to thefan assembly, heat exchanger, components thereof, rotation of fan 120(e.g., during use of fan 120), a 20 g-30 g shock. Also, this flexingresistance may be caused by or a result of the material, shape,surfaces, angles of surfaces (e.g., of surface 544 and/or surface 584)and/or size of hook 140 and/or tab 180.

For instance, materials included in the snap hooks, arms, and receivingtabs may be plastic, metal, semiconductor, organic material, inorganicmaterial, and polymers. Similarly, materials included may be materialsthat meet the stated generic material type: Polybutylene Terephthalate(PBT). Materials included may have the following material properties:tensile yield strength 120 megapascals (MPa); percent elongation atbreak>=4%; Flexural modulus>=7000 MPa; and/or heat deflection (HDT)>=109degrees Celsius. The material may comprise a thermoplastic polybutyleneterephthalate (PBT) twenty percent through thirty percent nylon glassfilled (GF) or equivalent, or an equivalent material having criticalmechanical material properties including tensile yield strength greaterthan 120 MPa, percent elongation at break greater than or equal to fourpercent, flexural modulus greater than or equal to 7,000 MPa and lessthan equal to 9,800 MPa.

According to some embodiments, edge 620 of hook 140 may not extend outto front surface 582 of tab 180 (e.g., as shown in FIG. 6 c). In somecases, edge 620 may not extend radially beyond surface 582 (e.g.,surface 546 may be shorter or extend radially outward less distance thansurface 594). Alternatively, edge 620 may extend radially beyond surface582.

It can also be appreciated that spacing tolerances between surfaces,assemblies, features and/or components described above may be includedin the systems without detracting from the concepts above. For instance,spacing tolerances, may provide spacing between surfaces of pair ofhooks 140 and tabs 180 defining opening 590, such as tolerances to allowfor receiving of the hooks by the surfaces defining the opening andengagement of the hooks by the surfaces defining the opening.Specifically, FIG. 6 c shows a small gap between surface 594 and surface596. This gap may be sufficient or necessary for the hook to be properlyreceived and snapped into the surfaces defining opening 590 to provideengagement (e.g., snapped engaged by the receiving tabs). Similarly, thesnap hooks and receiving tabs may be designed (e.g., have a shape, size,and/or material sufficient) so that the snap hooks “over travel” whentransitioning from being received to being engaged by the surfacesdefining the opening. Likewise, concepts described herein consider parttolerances and geometry not being perfect, such as deviations frommanufacturing that are known and/or tolerated.

Similarly, it is considered that the descriptions herein for fanattachment 130, cap 170, receiving tab 180, snap hook 140, features andcomponents thereof may be used to attach a fan to various othermachines, devices, surfaces, components, and the like for cooling orblowing air, whether or not the cooling or blowing air is for anelectronic device. For example, the heat exchanger may be optional, asoften the fan is used to directly cool or blow on the electronic devicewithout blowing on the heat exchanger. Thus, the fan attachment and/orfan assembly may blow air onto or be thermally coupled to an electronicdevice, such as a chip package, semiconductor chip, and/or a processor.In this instance, the features of the heat exchanger assembly may existon a device that does not have a heat exchanger.

In the foregoing specification, specific embodiments are described.However, various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of embodiments as set forthin the claims. The specification and drawings are, accordingly, to beregarded in an illustrative rather than a restrictive sense.

1. A fan attachment comprising: a generally disc shape having a topsurface, a bottom surface, and a ring shaped outer perimeter surfacehaving arms, the arms defining a plurality of openings through the discshape between the outer perimeter surface and a center axis of the discshape, the arms having ends defining a plurality of slots through theouter perimeter surface and to the openings; a plurality of pairs ofadjacent snap hooks on the outer perimeter surface, each snap hookhaving a wedge shape pointing from the top surface towards the bottomsurface and extending radially outwards from the outer perimeter surfaceon either side of a slot.
 2. The fan attachment of claim 1, wherein eachwedge shape includes a top surface parallel to the top surface of thedisc shape, an outside side surface perpendicular to the top surface ofthe disc shape, an inside side surface perpendicular to the top surfaceof the disc shape, and a lower surface extending from the outerperimeter surface to the top horizontal surface.
 3. The fan attachmentof claim 2, wherein the inside side surface of each snap hook faces aninside side surface of another snap hook, and the lower surface extendsbetween the outside side surface and the inside side surface of eachsnap hook.
 4. A system comprising: a fan attachment having a topsurface, a bottom surface, a ring shaped outer perimeter surface havingarms, and a plurality of pairs of adjacent snap hooks on the outerperimeter surface and extending radially outwards from the outerperimeter surface on either side of a slot, the arms defining aplurality of openings through the disc shape between the outer perimetersurface and a center axis of the disc shape, the arms having endsdefining a plurality of slots through the outer perimeter surface and tothe openings through the disc shape; a heat exchanger having a cap, thecap including a plurality of receiving tabs, wherein each pair ofadjacent snap hooks has a plurality of surfaces to be received by andengaged by a plurality of corresponding surfaces defining an opening ofa receiving tab.
 5. The system of claim 4, wherein each snap hookfurther comprises: a lower surface angled away from the outer perimetersurface to cause an upper surface of the receiving tab to flex away fromthe snap hook when the snap hook is being received by the correspondingsurfaces; a top surface disposed away from the heat exchanger andextending perpendicular to the outer perimeter surface to engage acorresponding top inner surface defining the opening of the receivingtab; an outside side surface disposed perpendicular to the outerperimeter surface to engage corresponding a side inner surface definingthe opening of the receiving tab.
 6. The system of claim 4, wherein thesnap hooks are on the ends of the arms, the receiving tabs are on anupper surface of the cap, and the receiving tabs and arms comprise amaterial having a flexibility to allow the arms to return to an originalshape after receipt and during engagement of the snap hooks by thereceiving tabs.
 7. The system of claim 4, wherein: the fan attachment isattached to the cap of the heat exchanger and is attached to a fan, thetop inner surface is adjacent to the top surface, and the side innersurface is adjacent to the outside side surface during one of rotationof the fan at a speed sufficient to provide cooling and a physical shockhaving a force of between 20 and 30 g-forces to the heat sink.
 8. Thesystem of claim 4, wherein each receiving tab comprises a generallyrectangular shape extending perpendicular and away from the an uppersurface of the cap at a location corresponding to a location of the snaphooks, the a rectangular shape having a front surface, a back surface,outer surfaces and inner surfaces defining the opening of the receivingtab.
 9. The system of claim 4, wherein the receiving tabs comprise: anangled upper surface to cause angled lower surfaces of a pair of snaphooks to flex away from the receiving tabs when the snap hook is beingreceived by the receiving tab; a top inner surface to engage topsurfaces of a pair of snap hooks when the snap hook is engaged by theplurality of corresponding surfaces defining an opening of a receivingtab; and a pair of side inner surface to engage outside side surfaces ofa pair of snap hooks when the snap hook is engaged by the plurality ofcorresponding surfaces defining an opening of a receiving tab.
 10. Thesystem of claim 4 wherein the fan attachment is coupled to a motor andthrough bearings to a fan, wherein the receiving tabs and snap hooks aredisposed between the heat exchanger and the fan, and wherein the fanattachment is disposed between a cap of the heat exchanger and the fan.11. The system of claim 4 wherein the heat exchanger includes aplurality of vanes extending radially away from the cap below the fan,the vanes thermally coupled to a processor, the thermal couplingincluding one of a liquid coolant and a solid heat exchange material,wherein the cap defines a cylinder under the fan attachment.
 12. Thesystem of claim 11 wherein the receiving tabs extend upward from thecap, away from the cap and vanes at radial positions around a topsurface of the cap, the snap hooks extend radially outward from an outerradial surface of the fan attachment, and each pair of snap hooks arereceived and engaged by the plurality of corresponding surfaces definingan opening of a receiving tab.
 13. The system of claim 1 wherein the fanattachment further comprises a keying and shear load feature to alignthe fan attachment with an index of a cap having the receiving tabs. 14.The system of claim 13 wherein the keying and shear load feature indexesthe fan attachment during receiving of the fan attachment by the cap andresist rotation and provides shear resistance for the fan attachmentduring rotation of the fan.
 15. The system of claim 1 wherein the snaphooks are snap-in type hooks or spring snap type hooks snapped into theplurality of corresponding surfaces defining an opening of the receivingtabs to maintain attachment between the fan attachment and the receivingtab during a 30 g shock to a system board that the receiving tabs arecoupled to.
 16. The system of claim 15 wherein the receiving tabs arepart of a cap coupled to a heat exchanger; and wherein the fanattachment further comprises: a wire management feature to route powerand control wires from a fan motor of a fan coupled to the fanattachment to a power header for plugging into a power source, and toprevent the wires from contacting blades of the fan as they rotate; athermister notch having a geometry to provide clearance to a thermistercomponent attached to a fan motor control printed circuit board (PCB)for sensing a temperature of ambient air around the fan; Z-heighttolerance springs to lifting the fan attachment away from the receivingtabs to hold the snap hooks against a top inner surface of the receivingtabs.